Blowpipe



BLOWPIPE Filed Nov. l, 1939 INVENTOR WI LGOT J. JACOBSSON Patented Dec. 2, 1941' BLOWPIPE Wilgot J. Jacobsson, Plainfield, N. J., assignor to Oxweld Acetylene Compamr, a corporation of West Virginia Application November 1, 1939, Serial'No. 302,284

11 Claims.

This invention relates to blowpipes in which the removal and replacement of parts requiring repair or substitution may be accomplished quickly and easily.

Blowpipes are usually constructed with gas mixer tubes and injectors so dimensioned as to give good operating characteristics over a narrow range of gas pressures and volumes. Consequently, when the characteristics of the desired flame require gas pressures and volumes outside the range provided for, it is necessary to replace the injector, and often the mixer tube as well, with parts designed to produce the desired flame characteristics. Likewise, when either the mixer tube or injector, or both, are damaged in service, as by flashbacks, the damaged part or parts must be removed and repaired, or replaced by new in breaking the numerous soldered, welded, or'

other coupling joints, and the possibility of damaging or losing the large number of individual parts requiring removal.

The objects of this invention are to provide a blowpipe in which the mixer tube and injector member may be removed and replaced quickly and easily without requiring the dismantling of end to the head H, extends through the bore in the body B and is adapted to be withdrawn rearwardly from the blowpipe through this bore with the head H maintained in fixed spaced relation to the body B. Secured within the mixer tube M is a removable injector member I which is'adapted to be withdrawn rearwardly from the mixer tube M through the rear end thereof; Fuel gas and combustion-supporting gas are supplied to the mixer tube M and the injector 1, respectively, through suitable inlet connections A and 0 and connecting passages in the rear body B. For convenience, the terms acetylene and "oxygen will be used throughout the rest of the specification to denote, respectively, any suitable fuel gas and any suitable combustion-supporting gas.

The head H of the improved blowpipe has a passage ll communicating at its front end with a welding tip T, secured to the head H in any well-known manner as by the coupling nut l2,

and communicating at the rear with an enlarged internally threaded socket I3 in the rear end of the head H.- Connecting the head H to the body B, and holding the head and body in fixed relation to one another, is a tubular handle C which fits at its front end over the head H and is secured thereto, as by silver soldering. The handle other parts of the blowpipe; in ,which the mixer tube and injector member together may be rcmoved and replaced as a unit; and in which the injector member may be removed and replaced individually. Still nother object is to provide such a blowpipe having a readily removable mixer tube and injector member, as well as provision for positive, safe, and uniform gas supply and distribution to the mixer tube and injector member.

The above and other objects will become ap-' parent from the following descriptionftaken in conjunction with the annexed drawing in which:

Fig. 1 is a longitudinal sectional view of a blowpipe embodying the principles of the invention; Fig. 2 is a cross-sectional view taken on the line 22 of Fig. 1; and

Fig. 3-is a cross-sectional view taken approximately on the line 3-3 of Fig. 1.

As shown in the drawing, the improved blow- ,pipe comprises, briefly, a head H connected by a tubular handicC to a rear body B having a longitudinal bore extending therethrough. A removable mixer tube M, which is secured at its front C fits at its rear end within a socket H in the front of the body B and is secured therein" by means of 'a' cup-shaped annular coupling nut IS on the outside of the handle engaging an externally threaded portion 16 of the body B and bearing against an annular wedge-shaped soft metal gasket H, to provide a leak-proof joint.

The longitudinal bore [8, which extends completely through the rear body B from front to rear, has an annular shoulder l9 adjacent to its front end, an annular inset recess 20 spaced 2. short distance rearwardly of the shoulder I9, a threaded portion 2| in back of the recess 20, and an annular flaring rear end portion 22.

An elongated removable mixer tube M, having a combustible gas mixture conduit 23 therein and an injector chamber 24 in back of the mixture conduit, is threadedly secured at its front end to the head H within the socket l3 with its front threaded section 28 on the mixer tube M coopcrates with the threaded portion 2| of the bore Hi to secure the mixer tube M to the body B. A gas-tight seal is provided at the rear end of the bore It by means of an annular wedge shaped soft metal gasket 23, which is wedged against both the body B and the external surface of the mixer tube M within the flaring portion 22 of the bore l8 by a nut 38 threaded on the'protruding portion 26 of the mixer tube. L

An annular recess 3| in the external surface of the mixer tube M, between the shoulder 21 and the threaded portion 28, registers with the annular recess in the body B and communicates with the injector chamber 24 by means of a plurality of radial ducts 32 extending through the wall of the mixer tube. Acetylene gas for distribution through the ducts 32 is supplied to the annular gas-distributing chamber formed by the two registered recesses 20 and 3|, through a passage 33 leading from the acetylene inlet A.

A second external annular recess 34 on the mixer tube M in back of the cooperating threads 2| and 28, which form a seal between the two longitudinally spaced recesses 3| and 34, communicates with the injector chamber 24 through a plurality of radial ducts 35 extending through the wall of the mixer tube. Oxygen gas for distribution through the ducts 35 is supplied to the annular recess 34, through a passage 38 leading from the oxygen inlet 0.

From the foregoing description, it is evident that the mixer tube M is rotatable and axially movable relatively to the head H and the body B and may be disconnected and withdrawn easily and quickly rearwardly from the blowpipe through the longitudinal bore |8 with the head member H maintained in position. This may be accomplished simply by turning the nut 30 to release the pressure on the gasket 29, turning the mixer tube M, by means of a wrench or other suitable tool applied to the protruding portion 25, until the threads are disengaged from the head H and body B, and then sliding the mixer tube rearwardly through the bore IS. The steps of inserting a new or repaired mixer tube ar accomplished in reverse order.

An injector member I have a longitudinal passage 31 is disposed within the injector chamber 24 of the mixer tube M in spaced relation to the internal wall of the mixer tube and with its rear end spaced from the rear end of the mixer tube. The wall of the chamber 24 is threaded for a portion of its length and a locking screw 38 is threaded therein ahead of the ducts 35, with its front face bearing against the rear end of the injector I. An annular external shoulder on the injector member 1 adjacent to the rear end thereof thus is pressed against a cooperating internal annular shoulder in the chamber 24 to form a gas-tight seal 39 between the lateral ducts 32 and the ducts 35. The locking screw 38 has a passage 40, resembling a keyhole, which is adapted to admit gas to the passage 31 of the injector I, and also to permit the insertion of a tool for removal or insertion of the locking screw. Also threaded into the chamber 24 in back of the injector I is a closure for the mixer tube M, comprising a removable slotted screw plug 4| having a shoulder bearing against a cooperating shoulder in the chamber 24 to provide a gas-tight seal 42. The plug 4| is spaced at its inner end a short distance in back of the locking screw 38 and the ducts 35 to provide a cavity or space 43 into which the ducts 35 open.

To remove the injector I individually from the blowpipe, it is only necessary to back out the plug 4| and the locking screw 38, after which the injector may be withdrawn rearwardly through the rear end of the mixer tube M. Withdrawal of the injector I may be facilitated by providing an internally threaded socket 44 in its rear end into which an ordinary carriage bolt or similar device may be inserted to provide a handhold. The insertion of a new or repaired injector is accomplished by reversing the order of removal.

It is evident that the injector I and the mixer tube M may be removed or replaced together as an assembled unit, when desired, simply by withdrawing or inserting the mixer tube M by means of the protruding portion 28, which is independent of the injector member I, in the manner described previously,- while maintaining intact the engagement of the injector I therein. This feature is of particular advantage when the blowpipe is used on several different types of work requiring frequent changes in flame characteristics. When such is the case, the operator may keep on hand several different previously assembled units, any dcsired one of which may be quickly and easily inserted, after withdrawal of l the old unit, without requiring the separation of the injector from the mixer tube.

The improved blowpipe construction permits the ready removal and replacement of essential parts without requiring complete dismantling of theblowpipe. At the same time, this construc tion introduces no operating difficulties or hazards. distributed uniformly through the radial ducts 35 to the cavity 43, from which it is admitted through the locking screw 38 to the injector I, and thence is discharged in a high velocity aspirating stream across a, mixing gap into the combustible gas mixture conduit 23 in a wellknown manner. Leakage of oxygen to the atmosphere is prevented by means of the gas-tight seal formed by the annular gasket 29, and the seal 42 formed by the plug 4|.

Acetylene gas from the annular recess 3| is distributed uniformly through the radial ducts 32 to the space between the injector I and the internal wall of the mixer tube M, passes forward around the injector, and is aspirated into the high velocity oxygen stream issuing from the injector passage 31 to form a combustible gas mixture. The combustible gas mixture thus formed passes through the conduit 23, the head H, and the tip T, at th end of which it may be burned to provide a high temperature flame. Leakage of acetylene to the interior of the handle C is prevented by the gas-tight seal formed between the cooperating shoulders I9 and 21. Also, leakage between the oxygen and acetylene passages and spaces in back of the tip of the injector member I is prevented by the cooperating threads 2| and 28 of the bor l8 and the mixer tube M, respectively, and by the gas-tight seal 39 formed between the injector member I and the mixer tube M.

If desired, the blowpipe may be water cooled to prevent overheating by circulating water in thechamber 45 formed between the internal wall of the tubular handle C and the external surface of the mixer tube M. Water inlet and outlet passages 46 and 41, respectively, for this purpose, are shown in Figs. 2 and 3.

Although the principles of this invention are described as embodied in a particular type of blowpipe, it is evident that the scope of the invention is such that the principles thereof may Oxygen gas from the annular recess 34 is for supplying a-combustion-supporting gas to the be applied in other ways. The invention, therefore, is not to be limited to the particular embodiment shown and described.

I claim:

1. A blowpipe comprising a member having a gas mixture passage therein; a body having a bore extending therethrough; a removable mixer tube associated at the front thereof with said member in gas-tight relation thereto, and at the rear thereof disposed within said bore, said mixer tube being adapted to be withdrawn rearwardly from said blowpipe through said bore; an injector member engaged within said mixer tube; and means adjacent to the rear end of said mixer tube and independent of said injector member whereby said mixer tube may be withdrawn from said blowpipe with said injector member engaged therein.

2. A blowpipe comprising a head member; a body having a bore extending therethrough; means holding said head member in fixed spaced relation to said body; a removable mixer tube associated at the front thereof with said head member in gas-tight relation thereto, and at the rear thereof disposed within said bore, said mixer tube being rotatable and axially movable relatively to said head member and said body, and being adapted to be disengaged from -said blowpipe and withdrawn rearwardly from said blowpipe through said bore with said head member maintained in fixed spaced relation to said body: and an injector member engaged within said mixer tube.

3. A blowpipe comprising a head member; a body having a bore extending therethrough;

, means holding said head member in fixed spaced relation to said body; a removable mixer tube associated at the front thereof with said head member in gas-tight relation thereto, and at the rear thereof disposed within said bore, said mixer tube being rotatable and axially movable relatively to said head member and said body, and being adapted to be disengaged from said blowpipe and withdrawn rearwardly from said blowpipe through said bore with said head member maintained in fixed spaced relation to said body; and a removable injector member disposed within said mixer tube, said injector member being adapted to be withdrawn rearwardly from said mixer tube through the rear end thereof.

4. A blowpipe comprising a tubular handle; a head member at one end of said handle; a body at the opposite end of said handle having a bore extending therethrough; a mixer tube engaged at the front thereof to said head member and at the rear thereof disposed within said bore, said mixer tube being rotatable and axially movable relatively to said head member and said body, and being disengageable from said head member and adapted to be withdrawn rearwardly from said blowpipe through said bor with said head member maintained in position; an injector member engaged within said mixer tube in spaced relation to the internal wall thereof, said injector member having a gas passage therein, said injector member providing a second gas passage between the external wall thereof and the internal wall of said mixer tube, said injector member being adapted to be withdrawn rearwardly from said mixer tube through the rear end thereof, and said injector member also being removable from said blowpipe together with said mixer tube as a unit; means for supplying a fuel gas to one of said gas passages; and means other of said gas passages.

5. .A blowpipe comprising a head member; a body having a 'bore extending therethrough; means holding said head member in fixed spaced relation to said body; a removable mixer tube engaged at the front thereof to said head member and at the rear thereof within said longitudinal bore, said mixer tube being rotatable and axially movable relatively to said head member and said'body, and being adapted to be disengaged from said blowpipe and withdrawn rearwardly from said blowpipe through said bore with said head member maintained in fixed spaced relation to said body; means providing a gastight seal between said mixer tube and said body 'between said injector member and said mixer tube ahead of the last-named seal means; and,

means for supplying a second gas to said injector member in 'the rear of the last-named seal means.

6. A blowpipe comprising a head member; a body having a bore extending therethrough; means connecting said head member to' said body; a removable mixer tube engaged at the front thereof to said head member. and extending at the rear thereof through said bore. said mixer tube being adapted to be withdrawn rearwardly from said blowpipe through said bore; a removable tubular injector member engaged within said mixer tube in spaced relation to the internal wall thereof, said injector member having its rear end spaced from the rear end of said mixer tube, and said injector member being adapted to be withdrawn rearwardly from said mixer tube through the rear end thereof; means providing a removable gas-tight closure for said mixer tube spaced rearwardly from the rear end of said injector member; means for supplying a as to the space between saidinjector member and the internal wall of said mixer tube; and means for supplying a second gas to the space between the rear end of said injector member and said closure means.

7. A blowpipe comprising a head member; a body having a bore extending therethrough; means connecting said head member to said body; a removable-mixer tube engaged at the front thereof to said head-member, and extending at the rear thereof through said bore, said mixer tube having a portion thereof protruding from said body beyond the rear end of said bore, said mixer tube being adapted to be withdrawn rearwardly from said blowpipe through said bore; an annular gasket compressed against both the external surface of said mixer tube and said body adjacent to said bore to provide a gas-tight seal; means on the protruding portion of said mixer tube bearing against said gasket; a removable tubular injector member engaged within tight closure for said mixer tube spaced rearwardly from the rear end ofisaid injector member; means for supplying a gas to the space between said injector member and the internal wall of said mixer tube; means for supplying a second gas to the space between the rear end of said injector member and said closure means; and means for preventing gas leakage between such spaces.

8. A blowpipe comprising a head member; a body having a bore extending therethrough; means connecting said head member to said body; a removable mixer tube engaged at the front thereof to said head member and at the rear thereof to said body within said bore, said mixer tube being adapted to be withdrawn rearwardly from said blowpipe through said bore; a removable tubular injector member engaged within said mixer tube in spaced relation to the internal wall thereof, said injector member being adapted to be withdrawn rearwardly from said mixer tube through the rear end thereof; means providing a gas-tight seal between the internal wall of said mixer tube and said injector member adjacent to the rear end of the latter; means providing a removable gas-tight closure for said mixer tube spaced rearwardly from the rear end of said injector member; means providing two longitudinally spaced annular recesses between the external wall of said mixer tube and the wall of said bore; gas-passage means extending through the wall of said mixer tube between one of said recesses and the space between said injector member and the internal wall of said mixer tube ahead of said seal means; gaspassage means extending through the wall of said mixer tube between the other of said recesses and the space between the rear end of said injector member and said closure means behind said seal means; means for supplying a gas to one of said recesses; and means for supplying a second gas to the other of said recesses.

9. A blowpipe comprising a head member; a body having a longitudinal bore extending therethrough; means connecting said head member to said body; a removable mixer tubeengaged at the front end thereof to said head member, and

engaged at the rear thereof within said bore, i

said mixer tube being adapted to be withdrawn rearwardly from said blowpipe through said bore; means providing a gas-tight seal between said mixer tube and said body adjacent to each end of said bore; said mixer tube having two longitudinally spaced apart annular recesses in the external surface thereof, gas passage means in a blowpi communicating between one of said recesses and the interior of said mixer tube, and gas passage means longitudinally spaced from said aforementioned gas passage means communicating beto the internal wall thereof, said injector memher being adapted to be withdrawn rearwardly from said mixer tube through the rear end thereof, and also being adapted to be withdrawn rearwardly from said blowpipe as a unit with said mixer tube; means providing a gas-tight seal between said mixer tube and said injector member intermediate said longitudinally spaced communicating gas passage means; means providing a gas-tight closure in said mixer tube in back of the rear-most communicating 884: Massage means and the rear end of said injector member; means for supplying fuel gas to one of said annular recesses; and meansfor supplying combustionsupporting gas to the other of said recesses.

10. A gas-mixing unit adapted to be inserted comprising a head member, a body having a re extending 'therethrough, and means connetting said head member to said body; said unit comprising a mixer tube adapted to be inserted through such bore from the rear thereof and adapted to engage said head member; an injector member engaged within said mixer tube; and means adjacent to the rear end of said mixer tube and independent of said injector member whereby said unit may be inserted in or withdrawn from such bore.

11. A gas-mixing unit adapted to be inserted in a blowpipe, said unit comprisinga mixer tube; an inJector member engaged within said mixer tube in spaced relation to the internal wall thereof; means providing a gas-tight seal between said mixer tube and said injector member ad- Jacent to the rear end of the latter; closure means for said mixer tube in back of said nozzle and spaced from the rear end thereof to provide a cavity; means providing a plurality of ducts extending through the wall of said mixer tube and opening into the space between said injector member and the internal wall of said mixer tube ahead of said seal; and means providing a plurality of ducts extending through the wall of said mixer tube and opening into said cavity.

WILGOT J. JACOBSSON. 

